Lindahl A, Edén S, Albertsson-Wikland K, Isaksson O, Kostyo J L
Endocrinology. 1983 Jun;112(6):2054-8. doi: 10.1210/endo-112-6-2054.
The ability of GH to induce refractoriness to its own insulin-like effect in adipose tissue is highly specific for GH. Moreover, refractoriness to the insulin-like action of GH can be induced with low concentrations of GH in the range of 10 ng/ml. In the present study, the ability of plasma from normal rats to induce refractoriness to the effect of GH on the production of 14CO2 from [14C]glucose in epididymal fat pads from hypophysectomized rats was examined as a measure of a GH-specific biological effect of the plasma. Plasma levels of GH were measured by RIA. Without exception, preincubation of fat pads with plasma having immunoreactive rat GH (rGH) levels over 50 ng/ml induced refractoriness to GH, whereas plasma having immunoreactive rGH levels below 15 ng/ml did not exert this effect. In fat pads preincubated with plasma having immunoreactive rGH levels between 10-50 ng/ml, the effect of a second exposure to GH varied in a dose-dependent manner. Also, plasma pools that were diluted with buffer or plasma from hypophysectomized rats were unable to induce refractoriness when the calculated or measured levels of immunoreactive rGH were below 15 ng/ml. The results suggest that in terms of the ability of GH to induce refractoriness to the insulin-like effect of the hormone, a very good correlation exists between the biological and immunological activities of GH in plasma from normal undisturbed rats.
生长激素（GH）诱导脂肪组织对其自身胰岛素样作用产生不应性的能力对GH具有高度特异性。此外，10 ng/ml范围内的低浓度GH即可诱导对GH胰岛素样作用的不应性。在本研究中，检测了正常大鼠血浆诱导垂体切除大鼠附睾脂肪垫中GH对[14C]葡萄糖产生14CO2的作用产生不应性的能力，以此作为血浆中GH特异性生物学效应的一种衡量指标。采用放射免疫分析法（RIA）测定血浆GH水平。无一例外，用免疫反应性大鼠GH（rGH）水平超过50 ng/ml的血浆预孵育脂肪垫会诱导对GH的不应性，而免疫反应性rGH水平低于15 ng/ml的血浆则不产生这种作用。在用免疫反应性rGH水平在10 - 50 ng/ml之间的血浆预孵育的脂肪垫中，再次暴露于GH的效应呈剂量依赖性变化。而且，当计算或测量的免疫反应性rGH水平低于15 ng/ml时，用缓冲液或垂体切除大鼠的血浆稀释的血浆池无法诱导不应性。结果表明，就GH诱导对该激素胰岛素样作用的不应性的能力而言，正常未受干扰大鼠血浆中GH的生物学活性和免疫活性之间存在非常良好的相关性。
